<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="app"></div>
    <script src="./js/vue.js"></script>
    <script>
        const vm = new Vue({
            el:'.app',
            data:{
                msg:'xx'
            },
            methods:{
                changeMsg(){
                    console.log(changeMsg);
                }
            },
            beforeMount() {
                console.log("app beforeMount");
                console.log(this.msg);
                console.log(this.changeMsg);
                // console.log(this.$refs.app);
                console.log(this.$el);
            },

        })
        console.log(vm.$el);
    </script>
</body>
</html>